Apparatus for shaving curved stereotype plates



Oct. 5, 1937. A, H, HOWELL 2,095,032

APPARATUS FOR SHAVING CURVED STEREOTYPE PLATES Filed June 1, 1954 2' Sheets-Sheet 1 Patented Oct. 5, 1937 UNITED STATES PATENT OFFICE APPARATUS FOR SHAVING CURVED STEREOTYPE PLATES Application June 1, 1934, Serial No. 728,570 In Great Britain June 2, 1933 12 Claims.

This invention relates to apparatus for shaving curved stereotype plates, and more particularly to improved means for ensuring accurate shaving of the concave surfaces of plates which 5 are formed in known manner with printing areas on their convex faces at levels Varying to accord with varying depths of impression desired to be produced from the respective areas.

When such a plate is held against the inner face of a boring arch the slight irregularities in its printing surface are liable to throw the inner surface which is to be shaved out of concentricity with the shaving tool rotated within the arch, and in order to correct the inaccuracy thus pro- 15 duced, considerable time has to be expended in the application of make-ready to the printing cylinder on which the plate is subsequently used.

To minimize this disadvantage it has heretofore been proposed to interpose between the 20 plates and the arch an overlay of resilient material adapted to yield to the high parts of the plate, or an overlay in which the high and low parts of the plate are reproduced in reverse or in the form of a so-called boring mask or cut overlay having parts cut away corresponding to the high parts of the plate.

In the use of these overlays it has heretofore been necessary to insert them into and withdraw them from the arch simultaneously with the insertion and withdrawal of each plate-an operation which is attended by considerable difficulty, especially when the plates have to be inserted into and withdrawn from the arch while hot and when a plurality of identical plates have 3 to be shaved in succession.

In order to overcome these disadvantages, it is proposed, according to the present invention, tosupport an overlay within the arch independently of the plate to be shaved, so that it may 40 remain in operative position within the arch during the casting of any number of plates to which its form is adapted.

According to the preferred arrangement for carrying out the invention, the shaving arch is 45 provided with orifices extending through its crown, and these orifices communicate at the exterior of the arch with pipes of an air suction system whereby the overlay is held in position within the arch by suction.

50 In carrying out the invention the overlay may be positioned within the arch in accurate registration with the plates by inserting it into the arch with the first plate. Alternatively, where this method cannot be conveniently adopted (for 55 example when a boring mask is used in conjunction with hot plates), a dummy plate may be employed to which the overlay or mask is first releasably secured in correct position by means of registering devices or marks applied to the dummy plate and to the overlay, the dummy 5 plate with the overlay attached is inserted within the arch in a position corresponding to that occupied by the plates to be shaved, the overlay secured to the arch and released from the dummy plate, whereupon the latter is removed from the arch, leaving the overlay or mask supported in correct position within the arch.

The accompanying drawings illustrate one constructional form of apparatus for carrying out the invention. In the said drawings:-

Figure 1 is a plan view of the shaving arch showing adjacent portions of the machine frame and plate supporting rails;

Figure 2 is an underside view of the shaving arch;

Figure 3 is an end elevation of a dummy plate,

as viewed from the left of Figure 4;

. Figures 4 and 5 are respectively a plan and underside view of the dummy plate shown in Figure 3, and I Figure 6 is a sectional View, on an enlarged scale, of a detail.

As is well known in machines of this construction, a plate to be shaved in the arch I is pushed into the arch along rails Z, 3, and lifted into contact with the under surface of the arch I, while resting on movable sections of the said rails into position for the shaving operation.

For the purposes of the present invention the crown of the arch l is provided with a number of holes 4 extending through its crown and each connected at the exterior of the arch with a branch pipe 5 of an air suction system, which may conveniently comprise a main pipe 6 with which all the branch pipes 5 communicate, and 4,0 which is connected by a pipe I with an air pump (not shown).

In this constructional form of apparatus, the main pipe 6 is closed at one end by a fixed plug 8 and at the opposite end by a hinged valve 9, 4,5 which latter enables the system to be conveniently opened to atmosphere when required.

When an overlay is tobe inserted in the arch with the first plate to be shaved, it is placed in correct position on the plate While the latter is supported on the rails 2, 3, pushed into and raised within the arch in the usual way, the valve 9 being opened during the position of the plate within the arch and then closed so as to retain the overlay in proper position against the inner surface of the arch in readiness for the next 7 7 plate tobe shaved when the'fi rstplate is removed.

' the inner surface of After shaving of allthe plates for which that particulari overlay is to be employed, the valve 9. is

opened to permit the overlay to "fall away from a the arch by gravity for removal by hand.

Referringlnow to Figures 3, 4; and 5, the dumf" my'plate lflthere shown for positioninggan ov'ei' lay within the arch .preparatory to. thes'havinsof a series :of cast plates substantially corresponds in form with the plates to be shaved, andis provided with retractible pins l l, l2, which extend; through'the plate l and serve both as registeringpoints for positioning the overlay-on the dummyjf .platefla'ndffor releas ably securingthe" overlay i thereto.

. 'In the arrangementisho wn, thereare two 'ed'ge .pins H which are projectedthroughtheiplate *bynieans 0f cam plungers l3; and: two centre pins l2, the 'innerfends' of which bear against 7 arms on ,an'oscillatable' rod-l which canbe j actuated.to project the pins throughithefplate by j 1 1 Q in the registering position by throughthe plate and through theoverlay.

4.0 "I'he'dummy plate, In is then pushed intothe to locate the dumm mearisiof ahead i 6, extending beyondthe'endof theplate l0. .A'stopll. is fixed to the crownof thedummyplatewhich engages iwiththe edge of the crown of the arch'and determinesthe longitudinal position of the plat'e within the arch.

In the arrangementshown; this stop isadapted V V y plate inserted into the arch rrom the left of Figure 1. l 1 When using thediimmy plate just described, the overlay 'l8 'indicated by'the dot-and-dash ;;lines' in Figure: 3 is positioned thereon, for example :by registering marks which can be. correctly positioned with reference to a centre .line on the stop l1 and thepi'nsjll, I2; and secured thereto protruding the pins 1 arch to the extent determined by the position of depressedto the inoperative, position by contact with theinner surface of the arch. The-valve 9 j :is then closed, andthe' overlay held in pos'ition by. the suction 'thus appliedto the holes 4; The

dummy plate I0 can therrbe. lowered and removed from the arch I, leaving thetoverlay in the latter properly. positioned for the plates subsequentlyto r 'b'e'shaved.

' A plate-is raised within the'arch by'upwa'rdf f f movement of adjustable rails-constituting {viri 2'," 3,1and in certain construction's' of apparatus,

tually continuations within the arch-of; the rails the edge of the Z plateiwhlch rests on the extension preferably located in close proximityto the pins 7 V In the use of a boring mask or cut overlay, one or more of the cut away; portions thereof might possibly fall into register 'withrsome'of the holes 7 4, thereby weakening the suction applied to parts; of 'the'overlay covering the other l'iole's. .Toavoid thi's 'difiiculty aisafety valveias illustrated in Fig ure 6,is preferably providd in each of the branch;

pipes 5, consisting of a ball23 normally heldby gravity against}, the lower end" of the, respective pipe 5, and a seat '24 against which the ball. 23

portion'offthe overlay. V "Itis to be understood that tern capable of being adjusted'to place the holes 4 under'suction when applying and holding the" ing them to atmosphererwhenan overlay is not in use. N 7 s'j By the use 'of'the improvedapparatus according to the invention, accurate shaving of the plates with relation to any desired relief on the printing'surface, isassured without the inconveniences heretofore experienced.- in the use "Of overlays and a greatfsaving of time'is effected overlay in the arch'under' -air pressure duringthe removal of the overlay from the arch and open as regards-the applicationjof:make-readyto the 1 "the stopill and raised within.thefarchtobring the overlay intoclose contact'with the innersur face thereof. The pins ll, I2, aresimultaneously" 0f the raili2 is raised'earlierthan theedgeiwhich .rests.on the extensicn ofthe rail3. In order to:

guard against any displacement of the overlay which might'b'e causedbythese movementsthe dummy plate is provided along the edge which rests upon-the extension of therail-Z with a lat .overlayinthearchxis maintained'during the sub-' 'Tsequentraising of;the opposit e edge of-theplate. I0 j'assist .this action'fcertain of the holes pl are.

;eri,ng 20.

7' V erally extendingflange Ill-having a resilient cov .Therespective edge of theioverlay is bent over" into contact with theresilient covering 20,. and j "when that 'edgeof the dummy plategis raised into contact withtheflatundersurfacejl gofthe arch ;l 'pin's '22 projecting from that undersurface'enjgageythe'resilientpcovering 2fl-through the edge.

oft'he overlay sol'that the lateral osition 'of'the mosphere within the: arch.

,quently'used for printing;

{Having described my inventio r'd'eelare that 2 what Ilclaim'and. desire'to secure byLetters'Patentjis:

3 plate cylindersyonfwhich the plates are subse L'In' apparatus forshaving curved"stereotype j 7 plates, the combination'with afshavingarch'hav -v ing orifices extending through itszcrown; of a suction'system outside-the arch,'a pipe connect ing each of said orifices with the suction system, and a valveassociatedwith each orifice adapted automaticallyto close the'connection of there- V spective orifice with the suction system when the latter is operative .and the'orifice is open' to at- V 2. In apparatus for shaving curved stereotype plates, the combination with a shaving arch].

havingorifices extendingthroughitscrown, of;

a'suction system outside the arch, a pipe connecting-each' of said orifices with the suctio n'system, a valve in the suction system adjustable to open said system to atmosphere, and a valve associated Witheach orifice adaptedj automatically-to close shaved, and means 'adaptedto secure in contact with the outer surface of the dummy plate an V overlay for applate' to' be shaved 4. In or for apparatus for sh-avin'g'curved ster eotype plates comprising a shaving archQa dummy, 'plate adapted;tooccupywithinthe shaving arch V 7 7 a positioncorresponding'to that of a plate tobe ,1

{.shaved, and means manually actuated to secure 60." :the connection of the respective orifice to thef I V suction systern'when the. latter is. operative'and i I the orifice is open to atmosphere 'withinthe arch.

i 3. In 'or for apparatus for shaving curved stereotype platescomprising a shaving arrzhya dummy plate adapted to occupy withinthe shaving arch j a position corresponding'to that of .a plateit'o be to the outer surface of the plate an overlay for a plate to be shaved and automatically actuated to release the overlay from the dummy plate when the latter is positioned within the shaving arch.

5. In or for apparatus for shaving curved stereotype plates comprising a shaving arch, a dummy plate adapted to occupy within the shaving arch a position corresponding to that of a plate to be shaved, and retractible pins extending through the plate from the interior thereof and adapted to engage an overlay surrounding the plate.

6. A dummy plate according to claim 3, including a stop for determining the longitudinal position of the plate within the shaving arch.

7. A dummy plate according to claim 3, including a laterally extending flange along one edge provided with a resilient covering.

8. In or for apparatus for shaving curved stertyp p at s mpris ng a shaving arch, a dummy plate corresponding in form with a plate to be shaved and provided with pins retractible by contact with the shaving arch adapted to engage an overlay surrounding the dummy plate, a stop adapted to determine the longitudinal position of the shaving arch, a laterally extending flange along one edge, and a resilient covering for the said flange. '7

9. In or for apparatus for shaving curved stereotype plates comprising a shaving arch, a dummy plate adapted to be inserted within the arch, said dummy plate corresponding in form with a plate plates, the combination with a shaving arch hav- Y ing orifices extending through its crown of a main 7 suction pipe outside the arch, branch suction pipes connecting said main suction pipe with the orifices, a valve in the main suction pipe adjustable to close and open said pipe to atmosphere, and a valve associated with each orifice adapted automatically to close the respective branch pipe when suction is applied to the open orifice through said branch pipe.

11. The method of preventing distortion of the inner surfaces of a series of duplicate printing plates which consists in supporting an overlay against a surface, placing a printing plate on'the overlay, shaving the opposite surface of said plate, removing the plate while leaving the overlay in place, and placing the next plate on the overlay.

12. The method of preventing distortion of the inner surfaces of a series of duplicate printing plates which consists in holding an overlay against a surface by suction, placing a printing plate on the overlay, shaving the opposite surface of said plate, removing the plate while leaving the overlay in place, and placing the next plate on the overlay.

AARON HENRY HOWELL. 

